Education secretary Michael Gove has been accused of creating schools for the middle classes after it was revealed that more than a third of his "free schools" will open in the most affluent areas.

The government promised to provide all children with "access to the kind of education only the rich can afford" when it launched the policy of allowing parents to set up schools free from local authority control. However, an analysis of the 32 free schools set to open in the next academic year shows 13 are in the most affluent half of England with only two in the 10% most deprived areas and 10 in the 20% most deprived areas, as ranked by the government's English Indices of Multiple Deprivation, 2010.

Less than a fifth of them are opening in the north of England, while half are set to open in the south and southeast.

Critics claim many free schools will offer little benefit to the disadvantaged as initially proposed, but have been established by "sharp-elbowed, well-off parents" in affluent areas for middle-class children. It is also feared that free schools in poorer areas will drain other schools of high-attaining children with the most advantaged backgrounds, creating two-tier education.

The Observer has learned that a number of concerned groups are considering legal action to block free schools opening in their area. Clare Bradford, headteacher of Henbury School in Bristol, has written to the Department for Education to warn that she would seek judicial review should Bristol Free School's funding agreement be approved by the secretary of state.

Bristol Free School, set to be the largest of its kind in the country, opened an office last week in the leafy suburb of Westbury-on-Trym to interview parents. Its prospective headteacher, Richard Clutterbuck, brother of actor Andrew Lincoln, who starred in the BBC TV series This Life and Channel 4's Teachers, said the school was being set up in response to parental demand.

However, Bradford, who has seen the numbers of children achieving good GCSEs more than double in her four years at Henbury, said the new school, in a building previously owned by a private school, could be a disaster for the comprehensive system in the area.

"We already have around 145 surplus places and other secondary schools in the area also have places going, so this free school is just not necessary," she said: "Next year we would normally expect to attract an intake of 150 or 160 pupils, but I think if the Bristol Free School opens we will struggle to get 120 pupils. The fewer pupils I have, the smaller the range of subjects I can teach, it is as simple as that.

"The free school is being set up in an affluent area and will attract middle-class parents away from my school and they have aggressively marketed themselves to do so. The whole project is simply pandering to social prejudices. They haven't consulted with us either, and they have a legal obligation to do so, so we are now considering legal action."

David Wolfe, a barrister at Matrix chambers who specialises in education issues, told the Observer he had also been in talks with several groups over potential legal action: "The parents I am talking about are parents or governors in maintained schools in the areas that would be affected."

He added that legal battles had not yet been launched because a number of the free school projects initially proposed had been pulled at the last minute when the government tightened the regulations earlier this year.

However, he believed some free school projects were now being rushed through to circumvent battles in the courts: "It takes time to take legal action and some of these projects appear to have only been given the green light very late on, making it difficult for anyone to put together a legal case. The Bristol Free School received approval for its business case in May. There may be some cynical thinking going on."

The new type of schools are publicly funded but independent of local authorities. They will not have to hire staff with the qualified teacher status accreditation normally required in the state sector. And while they must have an open and inclusive admissions code, they can select on aptitude in certain subjects.

Journalist Toby Young's school in Hammersmith, west London, will select 10% of its pupils based on their aptitude for music and teach classics. The Maharishi school, in Ormskirk, Lancashire, will expect pupils to practise transcendental meditation during the school day and instructs that at least one parent also commits to meditate.

Gove said last year that he had received more than 700 "expressions of interest" in setting up a free school, but the DfE received less than half that number of firm proposals and, of the 323 that applied, only 32 are on course to open. Four are existing independent schools applying for state funding under the free school status, suggesting that many children who will benefit from the new schools enjoy comfortable backgrounds.

Michael Foley, headteacher of Great Cornard upper school in Suffolk, where two free schools are set to open in the next two years, believed Gove's policy would lead to segregation: "Whatever you think of free schools as a policy, we have argued for the intelligent application of that policy. But free schools are being opened ad hoc on the basis that there happens to be a building spare.

"No consultation, no consideration of what the impact is of the school opening in that area and, when every school is making cuts, to hear that the local free school is being given £4.5m for its buildings and has just 178 students but guaranteed funding for two years. You start to ask, where is the equality?

"It is causing a lot of angst and upset in the system and it is so potentially divisive, channelling one group from one background off from those from another background. What we have is a bun fight for the middle-class aspirational children: we have lots of glossy prospectuses and PR in order to recruit the children that are most likely to do well.

"And I don't buy this idea that admission is open to all. The minute you put Latin on the curriculum for the first few years or put pupils in stripey blazers, you will only recruit one kind of child, regardless of how many times you say your school is for everybody."

Rachel Wolf, founder of the New Schools Network, said a key reason why schools were opening in affluent areas was the availability of appropriate buildings: "I do think there is a long-term issue for the government. At the moment they are often dependent on local authorities being helpful with sites. That means that in local authorities which are hostile to reform, which are often inner city/deprived areas, it is very, very difficult to get a building. You can find ways around this when you're only dealing with 20 schools. You can't when you are dealing with hundreds."

The areas in the DfE analysis have an average population of 1,500, the size which best reflects the catchment area of a school. A department spokesman said: "The fact is that a third of the most advanced projects are in the most deprived 20% of communities in the country, and almost two-thirds are in the most deprived 50%. We have huge interest coming through for scores more projects in poor areas, as well as many proposals for other communities facing an acute shortage of places."

• The following correction was printed in the Observer's For the record column, Sunday 19 June 2011. Contrary to a panel on schools, the Maharishi School in Ormskirk, Lancashire, will not require a child to learn transcendental meditation before being made an offer of a place and parents are not expected to learn to meditate ("Gove's free schools will divide pupils by social class, warn headteachers", News).